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Proposal of systems for targeted transoprt of compounds of sweet taste
Demová, Radoslava ; Hlaváček, Viliam (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on possibility of immobilization sweeteners on polymeric system. In the theoretical part information about sweeteners, carrier systems and the possibility of immobilization technique were reviewed. In the experimental part preparation of nanoparticles of polyhydroxybutyrate (PHB) was optimized. The PHB particles were characterized by dynamic light scattering (DLS). PHB particles were activated by plasma treatment. The surface morphology was studied using infrared and Raman spectroscopy. Immobilization of following substances with a sweet taste was tested: glucose, fructose, sucrose, mannitol, sorbitol and erythritol. From these compounds only sucrose was immobilized on PHB particles successfully. Prepared immobilized particles were exposed to the artificial stomach juice, intestinal juices and bile acids and amount of released sucrose was monitored. Finally, long-term stability prepared particles was measured and also the amount of sucrose released was determined.
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Chromatographic determination of simple sugars in selected beverages
Jurečková, Zuzana ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
An important part of the drinks are simple carbohydrates, because this thesis focuses on this issue. The theoretical part describes the characteristics , production , metabolism and the use of simple carbohydrates such as glucose, fructose and sucrose. There is also the definition of drinks and their main divisions . The literature review is based on the experimental part of analyzing selected beverages by high performance liquid chromatography with refractometric detection coupled to columns or alkyl ion-exchange phases. In conclusion, the results were compared to determine and comment . Nowadays the emphasis is on the correct functioning of the digestive tract. An important factor that supports the intestinal microflora is a prebiotic carbohydrate - tagatosa This could become tagatosa whose properties , production, metabolism in the body and any use is also included in the search . In the experimental part is listed possible optimization analysis of samples containing tagatosy on both types of columns in the HPLC system. The result is again commented in conclusion.
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Study of thermal properties of sucrose
Pecháčková, Kateřina ; Lucie, Trhlíková (referee) ; Zmeškal, Oldřich (advisor)
This work is focused on the study of thermal properties of materials that are used for accumulating heat on the basis of phase transition. These are mainly sugar alcohols (mannitol, erythritol) or carbohydrates (glucose) respectively. Thermal properties, thermal in particular, and thermal conductivity and specific heat capacity were measured in a wide range of temperatures comprising of the transformation from the solid to the liquid phase in the entire volume of substance. To study the temperature dependence of thermal properties, transient methods were used, that allow to determine the diffusion and relaxation time, thermal absorption coefficient and a parameter characterizing the properties of resources based on the fractal model of heat transfer (shape and the heating of the sample). Thermal parameters were determined from those values for defined ideal heat source (planar) and defined ideal heating (leap). There are results of three sucrose samples produced in the Opava refinery (unrefined, refined, clean). Differences in their thermal properties were studied. In addition, thermal properties of a pure solution (commercial) of sugar in distilled water at different concentrations were studied (1:1, 3:1, 1:3). The results presented in this thesis may be used to more efficient use of thermal energy in heating of dwellings, both with the use of solutions, which have a higher heat capacity than water and also with the use of phase transformation.
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Sucralose - a new permitted sweetener in Czech Republic
Chlebcová, Lenka ; Vránová, Dana (referee) ; Vespalcová, Milena (advisor)
This bachelor thesis deals with a topic of an artifical sweetner sucralose. The atention is given to process of production, using, its properties like sweetness, palatability and influence over human health, toxicity. In the food processing industry it is used by virtue of its high sweetness and low energy value. Determination methods of sucralose are capillary electrophoresis, liquid chromatography.
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Optimization of HPLC-ELSD method for determination of sugars in foods
Laba, Marija ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This master's thesis deals with the optimalization of HPLC-ELSD method for the determination of carbohydrates in food. The theoretical part focuses on the classification and characterization of carbohydrates, the occurrence of carbohydrates in food and their physiological importance. There was targeted mainly glucose, fructose, sucrose and maltose. There is a brief summary of the analytical methods that can be used to determine carbohydrates. Experimental part is based on a literary review. It also deals with high performance liquid chromatography with evaporative light scattering detector. The main content in this part is the optimalization of condition for reliable and rapid separation of the most frequently occurring carbohydrates in foods. The carbohydrates were identified and quantified under optimum condition in real samples specifically in fruit juice, beer, ketchup and red pepper powder. The result is commented in conclusion.
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Influence of selected coffee bean roasting technology on its chemical composition
Šajdlerová, Kristýna ; Mikulíková, Renata (referee) ; Diviš, Pavel (advisor)
The subject of this diploma thesis is the monitoring of chemical changes taking place in the coffee bean during roasting using various devices. For these purposes an industrial coffee roaster and a home roaster were used in the practical part. The theoretical part deals mainly with the characterization of coffee beans in terms of the content of various compounds and a description of the changes that occur during roasting. Different types of roasting machines are also presented. In the experimental part the roasting of coffee beans and the determination of the concentration of selected substances in the samples taken during roasting were performed. The monitored parameters included the concentration of sucrose, organic acids (citric, acetic, lactic, malic, formic and chlorogenic), caffeine and aromatic substances. One of the biggest differences found between the both roasters is the reduction in the concentration of chlorogenic acid, which decreased by 33 % for domestic equipment, while the decrease was almost doubled for industrial roasters. Another significant difference was also observed in the change in sucrose content. Sucrose degradation occurred in 94 % of coffee bean samples roasted on an industrial roaster, while only 75 % of the second type of roaster.
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Solid form of liposomal systems for inhalation
Fardová, Lucie ; Kalina, Michal (referee) ; Mravec, Filip (advisor)
This thesis deals with the preparation of solid liposomal systems for inhalation delivery. Liposomal systems were prepared by rehydration of a phospholipid film from dipalmitoylphosphatidylcholine. A sucrose solution used for film rehydration served as a protectant during spray drying. Additional liposome samples contained cholesterol, phosphatidic acid, or polyethylene glycol for better stabilization. The prepared liposome solutions were examined using scanning transmission electron microscopy, dynamic light scattering, and electrophoretic light scattering methods. Dried powders were measured using infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and determination of particle aerodynamic size. The results demonstrate the successful preparation of all liposomal systems, their drying into powder form, and subsequent reconstruction after rehydration with water or buffer. Based on the observed properties, liposomes with polyethylene glycol appeared to be the most suitable.
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Influence of selected coffee bean roasting technology on its chemical composition
Šajdlerová, Kristýna ; Mikulíková, Renata (referee) ; Diviš, Pavel (advisor)
The subject of this diploma thesis is the monitoring of chemical changes taking place in the coffee bean during roasting using various devices. For these purposes an industrial coffee roaster and a home roaster were used in the practical part. The theoretical part deals mainly with the characterization of coffee beans in terms of the content of various compounds and a description of the changes that occur during roasting. Different types of roasting machines are also presented. In the experimental part the roasting of coffee beans and the determination of the concentration of selected substances in the samples taken during roasting were performed. The monitored parameters included the concentration of sucrose, organic acids (citric, acetic, lactic, malic, formic and chlorogenic), caffeine and aromatic substances. One of the biggest differences found between the both roasters is the reduction in the concentration of chlorogenic acid, which decreased by 33 % for domestic equipment, while the decrease was almost doubled for industrial roasters. Another significant difference was also observed in the change in sucrose content. Sucrose degradation occurred in 94 % of coffee bean samples roasted on an industrial roaster, while only 75 % of the second type of roaster.
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Nutrigenomic analysis of diet influence in prenatal and early development on metabolic syndrome aspects manifestation in adulthood.
Školníková, Elena ; Šeda, Ondřej (advisor) ; Černá, Marie (referee) ; Malínská, Hana (referee)
16 Abstract The rising prevalence in noncommunicable diseases worldwide calls for the effort to determine their underlying causes. Common metabolic disorders in particular overwhelm the healthcare systems and are a one of the leading causes of poor quality of life of patients. Metabolic syndrome is represented by concurrence of several conditions - dyslipidaemia, obesity, hypertension or impaired glucose tolerance - altered metabolic phenotypes related to genetic and environmental factors. Recent studies suggest that early-life exposure to certain environmental stimuli is particularly capable of changing the mammalian phenotypes. Nutrition, as one of the major factors influencing health, is naturally a focus of research, which studies the link between parental diets and phenotypic alterations in offspring. The developmental origins of health and disease were historically more focused on maternal undernutrition, it is, however, more important to focus on surplus of macronutrients considering the westernization of modern diets. We propose the relevancy of not only the amount of macronutrients in maternal diet, but also their sources, as they may increase disease risk in offspring. Here we report, that sucrose as an alternative carbohydrate in maternal diet, has a marked impact on metabolism of the offspring...
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Effect of used sweeteners on sensory properties of fruit jams
PIHLÍK, Pavel
This thesis deals with the sorting and use of sweeteners in the production of fruit spreads. The theoretical part focuses on the sorting of sweetening agents and their classification. Furthermore, it presents procedures of production of fruit spreads and their assortment. The main goal is to compare sensory attributes of jams that I produced according to an assigned recipe, which is described in the practical part of this thesis. These jams were made from regional fruits (strawberries, apricots, sour-cherries) and sweetened with both natural (sucrose, sorbitol, Steviol glycosides) and artificial (sucralose) sweetening agents. The control group of this research were the students and employees of the University of South Bohemia in České Budějovice in the age of 24-60 years. The evaluators filled in a sequence test protocol and a questionnaire for consumers. The results of the sensory analysis were processed into tables and graphs with the aid of statistical methods.
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